Tetralogy of Fallot with coarctation of the aorta: a newly recognised developmental and anatomic syndrome

Origin of the left common carotid artery from ascending aorta in association with tetralogy of Fallot and hypoplastic right cervical aortic arch

We present a case of a 6-year-old girl with tetralogy of Fallot (TOF) and hypoplastic aortic arch with anomalous origin of left common carotid artery from the ascending aorta. The case highlights the importance of screening for abnormalities of aortic arch and arch vessels in TOF patients for accurate presurgical planning and to predict the postoperative outcomes.

The aortic arch in tetralogy of Fallot: types of branching and clinical implications

INTRODUCTION

Tetralogy of Fallot is the most common form of cyanotic CHD, with an incidence of 421 cases per million live births, constituting around 10% of CHD. Variations in aortic arch anatomy associated with tetralogy of Fallot, other than the incidence of right aortic arch (13-34%), are not frequently reported. A comprehensive analysis of a large number of tetralogy of Fallot cases is required to arrive at a compendious description of aortic arch anatomy.

MATERIALS AND METHODS

All patients with a diagnosis of tetralogy of Fallot who had CT or MRI either pre or post procedures between 1 January 2010 and 31 December 2019 at our hospital were included in the study. Using radiology consultants' reports and analysis of individual images, we identified the various morphological patterns of aortic arches prevalent in these patients.

RESULT

Out of 2684 patients who met the inclusion criteria, 1983 patients had left aortic arch (73.9%), 688 patients had right aortic arch (25.7%), four patients had cervical aortic arch (0.15%), eight patients had double aortic arch (0.3%), one patient had an aorto-pulmonary window (0.04%), and none of the patients had interrupted aortic arch. Sub-classification and clinical implications of the arch variations are described.

CONCLUSION

Up to 10% of tetralogy of Fallot patients may have significant anatomical variations of aortic arch that would necessitate changes or additional steps in their surgical or interventional procedures.

Ectopic lamellar Pacinian corpuscle within the thymus. Atypical or abnormal location?

Lamellar (Pacinian) corpuscle is a cutaneous encapsulated sensory corpuscle, mainly functioning as a rapidly adapting low-threshold mechanoreceptor with characteristic "onion skin"-like appearance. Even though the Pacinian corpuscle is typically located in the skin, histomorphologically and confirmed by using immunohistochemical methods, we have identified it within the interstitium of the thymus of a newborn with congenital heart defect. To the best of our knowledge, this is the first such account ever to be published. The structure of the thymic Pacinian corpuscle was the same as the Pacinian corpuscle in the skin. The ectopic thymic Pacinian corpuscle can be hypothetically explained as the consequence of impaired migration of neural crest cells, since neural crest-derived cells play an important role in the development of the Pacinian corpuscle, as well as the thymus and heart. In general, the occurrence of ectopic Pacinian corpuscle in different organs is rare. In the scientific literature, there are reports of its sporadic presence in the pancreas, in the lymph nodes, inside the prostate and the urinary bladder wall. Our report presents the first described case of the Pacinian corpuscle in a heterotopic location in the thymus. Similar to other incidental findings of this anatomic structure, explanation of its ectopic development, as well as its local function remains only speculative.

Aortic Coarctation Diagnosed During Pregnancy in a Woman With Repaired Tetralogy of Fallot

Aortic coarctation is thought to be a rare condition in patients with tetralogy of Fallot. We report the case of a 26 year old woman presenting with systemic hypertension at 17 weeks of pregnancy after repair of tetralogy of Fallot in childhood. Echocardiography and magnetic resonance imaging revealed right aortic arch with severe isthmic coarctation. Her blood pressure was controlled medically during the rest of her pregnancy, and delivery was uneventful. Successful transcatheter placement of a covered stent at the level of the coarctation was performed after delivery. To our knowledge, this is the first reported case of aortic coarctation diagnosed in an adult patient late after repair of tetralogy of Fallot.